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authorJan Glauber <jang@linux.vnet.ibm.com>2012-12-06 14:30:28 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-12-11 14:52:42 +0100
commit87bc359b9822a73f264f24f3c1b3e4e7e5ed7d72 (patch)
tree643e20ebffcf7eda13ad33c1bbeba82b306738c4 /arch
parent9163003236a52fd1a8ee6ca8a04f7232d001fc98 (diff)
s390/pci: speed up __iowrite64_copy by using pci store block insn
Benefit from pci store block instruction by writing up to 128 bytes with a single instruction to MMIO space. Depending on the workload this can result in a huge performance increase due to the reduced number of instructions. The ordering guarantees of single stores vs. one store block are identical. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/pci/pci.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index b0cef4db241..bc8935d3e5d 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -355,6 +355,12 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
return 0;
}
+/* combine single writes by using store-block insn */
+void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
+{
+ zpci_memcpy_toio(to, from, count);
+}
+
/* Create a virtual mapping cookie for a PCI BAR */
void __iomem *pci_iomap(struct pci_dev *pdev, int bar, unsigned long max)
{